Abstract
An arc chain model of multi-field coupling dynamics integrating the electromagnetic force, the thermal buoyancy force, the wind load force and the air resistance force of the secondary arc is established, and the motion equations of secondary arc for long-distance transmission lines are constructed. In addition, the arc root model is established after depth analysis of the formation and motion mechanism of the arc root, and the method of selecting optimal length of the current element is proposed. The motion trajectory and the arcing time of secondary arc are obtained with the established arc chain model, and the simulation results are compared with the experimental results to verify the validity of the proposed model. What's more, the arcing time and its dispersion with different wind speed and direction is calculated, and the results showed that the proposed arc model can effectively take into account of the wind influence factor. Finally the electromagnetic force, the thermal buoyancy and the wind load which imposed on the arc are calculated with different secondary current and wind speed, the results show that the wind load force has great influence on the secondary arc and the arc column is affected more greatly by wind than the arc root.